At Reason, Jacob Sullum has a few concerns about the information that came to light in a Department of Justice memo leaked to the media:
The Justice Department white paper on “The Lawfulness of a Lethal Operation Directed Against a U.S. Citizen Who Is a Senior Operational Leader of Al-Qa’ida or an Associated Force,” noted earlier tonight by Mike Riggs, fills in the fine print of the license to kill claimed by President Obama in several ways, none of them reassuring. The main conclusion of the paper, which was obtained by NBC News, is that “it would be lawful for the United States to conduct a lethal operation outside the United States against a U.S. citizen who is a senior, operational leader of al-Qa’ida or an associated force of al-Qa’ida without violating the Constitution or…federal statutes…under the following conditions: (1) an informed, high-level official of the U.S. government has determined that the targeted individual poses an imminent threat of violent attack against the United States; (2) capture is infeasible, and the United States continues to monitor whether capture becomes feasible; and (3) the operation is conducted in a manner consistent with the four fundamental principles of the laws of war governing the use of force” — i.e., “necessity, distinction, proportionality, and humanity.”
[. . .]
More generally, the white paper fleshes out the Obama administration’s argument that U.S. citizens killed by drones are getting all the process that is appropriate in the circumstances; hence the Fifth Amendment, though implicated, is not violated. And since these targeted killings are lawful acts of self-defense, the Justice Department says, they do not violate the law against killing U.S. nationals in foreign countries or the executive order banning assassination. After all, “A lawful killing in self-defense is not an assassination.” Duh.
The problem is that to accept this position, you have to put complete trust in the competence, wisdom, and ethics of the president, his underlings, and their successors. You have to believe they are properly defining and inerrantly identifying people who pose an imminent (or quasi-imminent) threat to national security and eliminating that threat through the only feasible means, which involves blowing people up from a distance. If mere mortals deserved that kind of faith, we would not need a Fifth Amendment, or the rest of the Constitution.